Bharatpedia:Reliable sources (medicine)

This page documents a content guideline for Bharatpedia. It is a generally accepted standard that editors should attempt to follow, though it is best treated with common sense, and occasional exceptions may apply. Any substantive edit to this page should reflect consensus. When in doubt, discuss first on the talk page.

This guideline supports the general sourcing policy with specific attention to what is appropriate for medical content in any Bharatpedia article, including those on alternative medicine. Sourcing for all other types of content – including non-medical information in medicine-related articles – is covered by the general guideline on identifying reliable sources.

Biomedical information must be based on reliable, third-party, published secondary sources, and must accurately reflect current knowledge. This guideline supports the general sourcing policy with specific attention to what is appropriate for medical content in any Bharatpedia article. Ideal sources for biomedical information include: review articles (especially systematic reviews) published in reputable medical journals; academic and professional books written by experts in the relevant fields and from respected publishers; and guidelines or position statements from national or international expert bodies.

Definitions

Types of sources

In the biomedical literature:

• A primary source is one in which the authors directly participated in the research and documented their personal experiences. They examined the patients, injected the rats, ran the experiments, or supervised those who did. Many papers published in medical journals are primary sources for facts about the research and discoveries made.
• A secondary source summarizes one or more primary or secondary sources to provide an overview of current understanding of the topic, to make recommendations, or to combine results of several studies. Examples include literature reviews or systematic reviews found in medical journals, specialist academic or professional books, and medical guidelines or position statements published by major health organizations.
• A tertiary source summarizes a range of secondary sources. Undergraduate or graduate level textbooks, edited scientific books, lay scientific books, and encyclopedias are tertiary sources.

Biomedical v. general information

Biomedical information requires MEDRS sourcing that complies with this guideline, whereas general information in the same article may not. For example, an article on a purported medical product could contain both biomedical and non-biomedical claims:

• "Dr Foster's pills cure everything." A biomedical claim – strong MEDRS sourcing is required here.
• "The pills were invented by Dr Archibald Foster and released onto the market in 2015." This is not biomedical information, and requires only ordinary RS.
• "They are purple and triangular, packaged one to a box." This is also non-biomedical and requires only ordinary RS.

Basic advice

Avoid primary sources

Per the Bharatpedia policies of neutral point of view, no original research, and verifiability, articles need to be based on reliable, independent, published secondary or tertiary sources. For biomedical content, the Bharatpedia community relies on guidance contained in expert scientific reviews and textbooks, and in official statements published by major medical and scientific bodies. Note that health-related content in the general news media should not normally be used to source biomedical content in Bharatpedia articles. (News sources may be useful for non-biomedical content, such as information about "society and culture".)

Primary sources should NOT normally be used as a basis for biomedical content. This is because primary biomedical literature is exploratory and often not reliable (any given primary source may be contradicted by another). Any text that relies on primary sources should usually have minimal weight, only describe conclusions made by the source, and describe these findings so clearly that any editor can check the sourcing without the need for specialist knowledge. Primary sources should never be cited in support of a conclusion that is not clearly made by the authors (see BP:Synthesis).

Respect secondary sources

Primary sources should not be cited with intent of "debunking", contradicting, or countering conclusions made by secondary sources. Synthesis of published material advancing a position is original research, and Bharatpedia is not a venue for open research. Controversies or uncertainties in medicine should be supported by reliable secondary sources describing the varying viewpoints. Primary sources should not be aggregated or presented without context in order to undermine proportionate representation of opinion in a field. If material can be supported by either primary or secondary sources, the secondary sources should be used.

Findings are often touted in the popular press as soon as primary research is reported, before the scientific community has analyzed and commented on the results. Therefore, such sources should generally be omitted (see recentism). Determining weight of studies requires reliable secondary sources (not press releases or newspaper articles based on such sources). If conclusions are worth mentioning (such as large randomized clinical trials with surprising results), they should be described appropriately as from a single study.

If no reviews on the subject are published in a reasonable amount of time, then the content and primary source should be removed. A reason to avoid primary sources in the biomedical field – especially papers reporting results of in vitro experiments – is that they are often not replicable (see also replication crisis) and are therefore unsuitable for use in generating encyclopedic, reliable biomedical content. Further, the fact that a claim is published in a refereed journal need not make it true. Even well-designed randomized experiments will occasionally produce spurious results, and experiments and studies can produce flawed results or even fall victim to deliberate fraud.

Summarize scientific consensus

Scientific journals are the best place to find both primary and secondary sources. Every rigorous scientific journal is peer reviewed. Be careful of material published in journals lacking peer review or which report material mainly in other fields, and of material published in disreputable journals or disreputable fields.

Bharatpedia policies on the neutral point of view and not publishing original research demand that we present prevailing medical or scientific consensus, which can be found in recent, authoritative review articles, in statements and practice guidelines issued by major professional medical or scientific societies (for example, the European Society of Cardiology or the Infectious Disease Society of America) and widely respected governmental and quasi-governmental health authorities (for example, AHRQ, USPSTF, NICE, and WHO), in textbooks, or in scholarly monographs. Although significant-minority views are welcome in Bharatpedia, such views must be presented in the context of their acceptance by experts in the field. Additionally, the views of tiny minorities need not be reported. Finally, make readers aware of controversies that are stated in reliable sources. A well-referenced article will point to specific journal articles or specific theories proposed by specific researchers.

Assess evidence quality

When writing about any health effect, assessing evidence quality helps distinguish between minor and major views, determine due weight, and identify accepted evidence-based information. Even in reputable medical journals, different papers are not given equal weight. Studies can be categorized into levels of evidence, and editors should rely on high-level evidence, such as systematic reviews. Low-level evidence (such as case reports or series) or non-evidence (such as anecdotes or conventional wisdom) are avoided. Medical guidelines or position statements by internationally or nationally recognized expert bodies also often contain recommendations, along with assessments of underlying evidence.

The best evidence for efficacy of treatments and other health interventions is mainly from meta-analyses of randomized controlled trials (RCTs). Systematic reviews of literature that include non-randomized studies are less reliable. Narrative reviews can help establish the context of evidence quality. Lower levels of evidence in medical research come from primary studies. Roughly in descending order, these include: individual RCTs; quasi-experimental studies; prospective observational (non-experimental) studies, such as prospective cohort studies; case control studies; cross-sectional studies (surveys), and other correlation studies such as ecological studies; other retrospective analyses; and non-evidence-based expert opinion or clinical experience. Case reports and series are especially avoided, as they are uncontrolled.

Several formal systems exist for assessing the quality of available evidence on medical subjects. Here, "assess evidence quality" essentially means editors should determine the appropriate type of source and quality of publication. Respect the levels of evidence: do not reject a high-level type of source (e.g., a meta-analysis) in favor of a source from lower levels of evidence (e.g., any primary source) because of personal objections to the inclusion criteria, references, funding sources, or conclusions in the higher-level source. Editors should not perform detailed academic peer review.

Use up-to-date evidence

Keeping an article up-to-date while maintaining the more-important goal of reliability is important. These instructions are appropriate for actively researched areas with many primary sources and several reviews and may need to be relaxed in areas where little progress is being made or where few reviews are published.

• In many topics, a review that was conducted more than five or so years ago will have been superseded by more up-to-date ones, and editors should try to find those newer sources, to determine whether the expert opinion has changed since the older sources were written. The range of reviews you examine should be wide enough to catch at least one full review cycle, containing newer reviews written and published in the light of older ones and of more-recent primary studies.
• Assessing reviews may be difficult. While the most-recent reviews include later research results, this does not automatically give more weight to the most recent review (see recentism).
• Prefer recent reviews to older primary sources on the same topic. If recent reviews do not mention an older primary source, the older source is dubious. Conversely, an older primary source that is seminal, replicated, and often-cited may be mentioned in the main text in a context established by reviews.

There are exceptions to these rules of thumb:

• History sections often cite older work.
• Cochrane Library reviews and NICE guidelines are generally of high quality and are periodically re-examined even if their initial publication dates fall outside the 5-year window.

Searching for sources

Bharatpedia articles should cite high-quality reliable literature, regardless of whether the literature requires a subscription or is free to access. Editors should not be deterred from citing a source simply because it is behind a paywall, though they should make an effort to verify the content through other means where possible. Where a paper's abstract is available but the full text is not, editors should take care not to draw conclusions that the abstract does not support.

See also

• Bharatpedia:Identifying reliable sources
• Bharatpedia:Verifiability
• Bharatpedia:No original research
• Bharatpedia:Neutral point of view
• Bharatpedia:Biomedical information
• Bharatpedia:Manual of Style (medicine-related articles)
• Bharatpedia:WikiProject Medicine